A variety of three-dimensional printing techniques exist to reproduce essentially any object with a desired exterior. However, for an object with a given exterior, there are many ways to fill the enclosed, interior volume, a process generally referred to as infilling. For example, one can fill the entire volume with build material, which increases strength but takes longer and uses more material. Alternatively, a variety of regular or varying geometric patterns can be used, or no infill at all can be used, which leads to a minimum use of build material and a reduction in build time, but may produce a highly fragile printed object. There remains a need for improved infilling techniques for three-dimensional printing.